What Causes Dry Skin Along With Red Blisters In An Infant?

Hi, My son is 19 months old, I observed the dry skin in winter and he got red bubbles which gets spreded.. when i asked doctor they said it is sting bite. And consulted pediatrician and one dermetologists.. both suggested different medicines.. finally i consulted one dermetologists, she suggested to use cetaphil cleansing and mosituring bar soap and venusia max intensive mositurising cream to apply in whole body evenly after bath. please suggest is it compulsory to use the mositurising cream or using soap itself enough.. or is it safe to use both (suggested soap and mosituriser for my son).. will it give any issue in future for my son if the mositurising cream is not used. thanks in advance for your guidance.